Following the Guernon case in the mid 2000s, captain Pierre Niémans was transferred to the head of the Central Office against violent crime (OCCS). This new confidential unit deals with the most complex cases, where the clues are few and where serial murders must be resolved as quickly as possible. It is during a particularly difficult mission that Niémans stumbles upon his best pupil and spiritual daughter, Camille Delaunay.
